Escapement mechanism



P 1961 A. BURSTEIN 2,998,873

ESCAPEMENT MECHANISM Filed Nov. 27, 1957 IN V EN TOR.

17 I 9 a! BY United States Patent Cfitice Patented Sept. 5, 1961 2,998,873 ESCAPEMENT MECHANISM Albeit Burstein, Drexel Hill, Pa., assignor to Radio Corporation of America, a corporation of Delaware Filed Nov. 27, 1957, Ser. No. 699,460 7 Claims. (Cl. 192-40) This invention relates to escapement mechanisms, and more particularly to a control device for selectively engaging and disengaging a member and providing predetermined increments of motion thereof.

A simplified escapement mechanism is desirable to enable incremental advance or rotation of a movable member, which mechanism should be efficient in operation, inexpensive, and easily controlled.

Accordingly, an object of this invention is to provide a simple and eflicient escapement mechanism.

Another object of this invention is to provide an escapement mechanism which will permit selective movement of an overrunning clutch.

A further object of this invention is to provide an escapement mechanism to produce rotation of an overrunning clutch in two controlled steps, each of which may be of one-half revolution.

A still further object of this invention is to provide electromagnetic means for operating the escapement device to produce one revolution of a rotatable clutch member in half revolution steps for each actuating cycle of the electromagnetic means.

A still further object of this invention is to provide electromagnetic means for operating an escapement device to produce two controlled one-half revolutions of a rotatable clutch member for each actuating cycle of the electromagnetic means regardless of the duration of the electrical signal applied to the electromagnetic means.

The invention is especially adapted for use with a one-way overrunning clutch. In a preferred embodiment, the rotatable member of the clutch has two radially projecting lugs mounted diametrically opposite and axially displaced from each other. An actuating member of the escape mechanism is mounted transverse to the path of the rotatable member and is movable in a transverse plane between a first and second position. Projecting fingers are mounted on the actuating member and are separated by an aperture through which a lug may pass. When the actuating member is in the first position, one of the projecting lugs is held against one of the fingers and prevents rotation. When the actuating member translates from its first position to its second position, this lug slips through the aperture and allows incremental rotation of the rotatable member. Rotation stops when the second projecting lug contacts the second finger. When the actuating member translates back to its first position, the second lug slips through the aperture and allows another incremental advance of the rotatable member. Further rotation is stopped when the first lug again contacts the first finger. Axial displacement of the projecting lugs prevents more than one lug from passing through the aperture during one translating mo tion of the actuating member regardless of the relative speed of the moving members.

The foregoing and other objects, the advantages and novel features of this invention, as well as the invention itself both as to its organization and mode of operation, may be best understood from the following description when read in connection with the accompanying drawing, in which like reference numerals refer to like parts, and in which:

FIGURE 1 is a view, in front elevation, of a solenoid controlled escape mechanism, and in which the solenoid is shown in the de-energized position;

FIGURE 2 is a view similar to FIGURE 1 and i which the solenoid is energized;

FIGURE 3 is a View, in side elevation, of the assembly shown in FIGURE 2;

FIGURE 4 is a bottom view of FIGURE 3; and

FIGURES 5 and 6 are partial bottom views of a modification of the embodiment of FIGURES l to 4, and illustrating the solenoid escape mechanism in different positions.

Referring now to FIGURES 1-4 of the drawing, an overrunning clutch 1 includes a housing 9, an input shaft 3 connected to the housing, a rotatable collar 7 on which two radially projecting lugs 11 and 11' are mounted diametrically opposite and axially displaced from each other, and an output shaft 5. When the rotatable collar 7 is restrained from rotation, the output shaft '5 is disengaged from the input shaft 3. When the restraint on collar 7 is removed, the output shaft 5 is coupled to the input shaft 3 and motion of the output shaft 5 is allowed.

The escapement mechanism includes a solenoid or relay 13, an armature 15, a C-shaped actuator arm 17, a tension spring 23, and an L-shaped mounting frame 19. The upper leg of the actuator arm 17 is connected to the magnetic armature 15 which is located above the solenoid 13 and pivotally mounted to the side of frame 19. The central leg of actuator arm *17 is parallel to solenoid 13. A guide plate 20 is secured to the mounting frame 19 at the base of solenoid 13 and extends beyond the edge of frame 19. Plate 20 includes a slot 22 for guiding actuator arm 17 when it translates. An arm 2l1 projectslaterally from actuator arm 17 near its upper end. A tension spring 23 is connected between guide plate 20 and arm 21. An L-shaped leg 25 projects laterally from the central leg of actuator arm 17. This leg 25 supports an adjustable screw 27 which is adapted to bear against the side of mounting frame 19 when the solenoid 13 is tie-energized. Tension spring 23 forces actuator arm 17 to one end position of its travel path when solenoid 13 is de-energized. This position, hereafter referred to as the de-energized position, may be adjusted by changing the setting of adjustable screw 27. This may best be seen by referring to FIGURE 1. I

When solenoid 13 is energized, magnetic armatu-re 15 is attracted to solenoid -13. Armature 15 pivots and is pulled downward causing actuator arm 17 to move with it and assume a position at the other end of its travel path. This position, hereafter referred to as the energized position, is determined by a stop member 29 mounted between the top of solenoid 13 and armature 15. This position may best be seen by referring to FIG- URE 2.

, The lower leg of actuator arm 17 is located in a' plane transverse to the path of rotation of collar 7 and adjacent to collar 7. The lower leg of actuating arm 17 has two projecting fingers 3 1 and 361' separated by an aperture 35. This aperture is of suflicient size to allow projecting log 11 'or 11' of collar 7 to slip through when the aperture 35 is in the line of travel of the lug 11 or 11. Axial displacement of the lugs 11, 11 prevents more than one lug from slipping through aperture 35 during any one translation of actuator arm 17 regardless of the relative speed of the two members. These features may be seen by referring to FIGURE 4.

In operation, when the solenoid 13 is die-energized, actuator arm 17 is in its de-energized position, as shown in FIGURE 1, and finger 31 blocks the path of projecting lug .11 preventing rotation of clutch collar 7. When an energizing signal is applied to solenoid 13, actuator arm 17 translates to its energized position as shown in FIGURE 2. During the translating motion of actuating arm 17, lug 11' may slip through aperture 35 when the 3 aperture is adjacent'the path' of lug 11'. The collar 7 may now rotate one-half revolution. Projecting finger 31 then blocks the path of projecting lug 11 and prevents further rotation of collar 7, as shown in FIGURES 2 and 4. When actuatorarm 17 reaches its energized position, all motion is stopped until the energizing signal applied to solenoid 13 is removed, at which time tension spring 23 forces actuator arm 17 to translate to its deenergized position as determined by the setting of adjustable screw 27. Thisposition is shown in FIGURE 1.

During the translation of actuating arm 17 to its deenergized position, projecting lug 11 may slip through aperture 35 when the aperture is in the path of travel of lug 11. Clutch collar 7 may then rotate one-half revolution, further rotation being prevented by finger 31 which blocks the path of lug 11'. In this manner, collar 7 rotates through two complete and independent half revolutions for each cycle of operation of solenoid 13 (energize and de-energize).

A modification of the present invention, illustrated in FIGURES and 6, includes an actuator arm 17 having only one finger 31 instead of the two fingers 31, 31' previously described. In the de-energized position, finger 31 obstructs the path of lug 11 and prevents rotation of collar 7. When actuator arm 17 translates to its energized position, as shown in FIGURE 6, the path of lug 11 is no longer obstructed and collar 7 may rotate one-half revolution. Finger 31 then blocks the path of lug 11 and prevents further rotation of collar 7. When actuator arm 17 translates to its tie-energized position, the path of lug 11 is no longer obstructed and collar 7 may rotate another half revolution, further rotation being prevented when finger 35 obstructs the path of lug 11'.

Although this invention has been illustrated and described as a two-step, single revolution clutch actuator, it will be recognized that alterations and modifications will allow rotation of the clutch collar 7 to be selectively controlled in increments of other than half revolution steps by changing the position or number of projecting lugs on collar 7, or both, and the arrangement of finger openings.

It will be further recognized that the actuator arm 17 may be actuated by mechanical means as well as by electrical means. However, an electrical actuating means has certain advantages. For example, it may be made more responsive to the application of small energizing signals and is easily operated from a signal source remote to the escapement mechanism.

What is claimed is:

1. In combination with a movable member whose motion is to be controlled, an escapement mechanism including an arm having spaced fingers, said member having a plurality of spaced projecting lugs, adjacent ones of said lugs lying in a plane oblique to the path of movement of said member said arm being movable from a first position to a second position and vice versa, said fingers being located in and movable in a plane transverse to the path of said lugs, said fingers being separated by a space sufliciently large to pass said spaced lugs individually, each of said fingers being located to obstruct the path of a ditferent one of said lugs for each different said position of said arm, and means for selectively moving said arm among said first and said second position, thereby to control said motion.

2. In combination with a rotatable member whose motion is to be controlled, an escapement mechanism including an arm having spaced fingers and being movable from a first to a second position and vice versa, said member having radially projecting lugs angularly and axially displaced in fixed spaced relation to each other, said fingers being located in and movable in a plane transverse to the paths of said lugs, said fingers being separated by a space sufiiciently large to pass each of said lugs individually, each of said fingers being located to obstruct the paths of different ones of said'lugs 4 for particular positions of said arm, and means for selectively moving said arm among said first and said second position to effect the release of one of said lugs for each translation of said arm and thereby control the motion of said member.

3. In combination with an overrunning clutch, said clutch having a rotatable control member, said clutch being disengaged when the rotation of said control member is interrupted, an escapement mechanism including an arm having spaced fingers, said arm being movable reversibly between a first and a second position, said control member having two radially projecting lugs, said fingers being located in and movable in a plane transverse to the paths of said lugs, each of said fingers being located on said arm to obstruct the path of a different one of said lugs forsaid first and said second position of said arm respectively, said fingers being separated by a space sufiiciently large to pass each of said lugs individually, said lugs being angularly and axially displaced from each other to prevent passage of more than one of said lugs through said opening for any single position of said arm, and means including electromagnetically operable control means for selectively moving said arm between said first and second positions.

4. In combination with an overrunning clutch having a rotatable control member, said clutch being engaged when said rotatable member is free to rotate, an escapement mechanism including an arm movable among a first and a second position, said rotatable control member having two radially projecting lugs, said arm having spaced fingers movable in a plane transverse to the paths of said lugs, said fingers being separated by a space sufiiciently large to pass each of said lugs one at a time, said projecting lugs being positioned diametrically opposite and axially displaced from each other to prevent passage of more than one lug through said space for any position of said arm, each of said fingers being located to obstruct the path of a different one of said lugs for particular positions of said arm, electromagnetically operated control means for selectively moving said arm to one of said first and said second position when an energizing signal is applied to said electromagnetically operated control means, and a tension spring for returning said arm to the other said position when said energizing signal is removed from said electromagnetically operated means, said space between said fingers permitting passage of one of said lugs for each translation of said arm and efiecting release of said rotatable control member for rotation of one-half revolution twice during each operating cycle of said electromagnetic control means.

5. In combination with an overrunning clutch having a rotatable control member, a frame, an escapement mechanism including a solenoid mounted on said frame, an armature pivotally secured to said frame and actuated by said solenoid, an arm secured to said armature, and means to limit the motion of said arm between a first and second position, said rotatable member having two radially projecting lugs, said arm having spaced fingers mounted in and movable in a plane transverse to the paths of said lugs, said fingers being separated by a space sufiiciently large to allow passage of said lugs individually for selected positions of said arm, said fingers obstructing the path of said lugs for other positions of said arm, said projecting lugs being mounted diametrically opposite and axially displaced from each other on said rotatable member to prevent passage of more than one of said lugs through said space for any one position of said arm, said arm effecting release of said rotatable member twice during each operating cycle of said solenoid to allow one revolution of said rotatable member in two independent half-revolution steps.

6. In combination with a movable member whose motion is to be controlled, an escapement mechanism 0 including a movable arm, said member having a plurality of spaced projecting lugs, said arm being movable to a number of difierent positions in a plane transverse to the path of said lugs to block the path of a diflerent one of said lugs for each difierent one of said positions of said arm, and means independent of said movable member for moving said arm selectively among said different positions, thereby to control motion of said movable member.

7. In combination with a rotatable member Whose motion is to be controlled, an escapement mechanism including a single movable arm, said member having projecting lugs angularly and axially displaced from each other, said arm being movable to a number of different positions in a plane transverse to the path of said lugs, said arm being located to obstruct the path of a different one of said lugs after a selected angular movement thereof for each different one of said positions of said arm,

and means for moving said arm to said different tions during a complete operating cycle of said thereby to control motion of said member.

References Cited in the file of this patent UNITED STATES PATENTS Crane Nov. 20, Penfield et al. Dec. l7, Benecke Aug. 19, Nichols et a1. May 5, Lurtz Sept. 18, Wandrey July 12, Anderson Mar. 4, Denton et al. July 26,

FOREIGN PATENTS France Oct. 7,

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